By my calculations, if Rodney can get the car weight down to 1550lbs (with him),
it should run about 133mph.(based on that rear wheel number)
This is enough to get him into the very low 10s.(nines in a perfect world).
Bergs still hold the ss/c record at 10.38 I think,
so a trip up here to the winters may be worth while!
Would be nice to get the gear ratios done to suit.
133mph will be about 9000 in 3rd,
or 7000 in 4th.
Yeah, the right gear ratios would be nice. I think Rod has the right ratios but no time left now to change them, so it may not run that great on the weekend.
What surprised me with the motor was how broad and flat the power curve was, its definatly not peaky, the cam seems to work very well, which really surprised me. Big compression does wonders!!
Fantastic numbers Rod - congratulation thus far! I guess the proof is in the pudding so I look forward to seeing how it runs on the strip! Best of luck.
Alan
249 rear wheel horsepower is pretty damn tough. I'd love to here that thing doing 8500 rpm!
Do the recommended air/fuel ratios change with the different fuels?
Do you run less timing with these fuels than you would with premium pump gas?
My optimum total timing ended up at 35 degrees which seems like a fair bit. Out of interest are you only running 28 degrees total or is that the advance?
After 9 hrs and about 40 dyno runs I ended up with 249.7 hp and 451.1 ft lbs of torque at the rear wheels . According to the dyno operator this equates to 334 hp . I don't belive this to be exactly correct however he tells me that a week ago he had a brand new SS comodore on the dyno and it calculated out to be 305 kw , the factory specs say 307 kw . I am more than happy with the results and am now looking to run some good mid 10 sec passes on Sat . I have an electrical misfire @ 8400 rpm and today Owen rewired the car . I am hoping that this will fix the problem and I have more revs to use . I will remove the engine tomorrow and fit a new clutch that will be aggressive off the start line . I think that with the power that I now have it will launch really hard . Maximim power was 249 @ 8000 rpm however I feel that it may be a little higher if I can use all the revs available . It made 150 hp @ 5100 , 175 hp @ 5400 , 200 hp @ 5700 and 225 hp @ 6600 . Maxium torque was 451 ft lbs @ 5800 rpm and @ 8200 rpm was still around 375 ft lbs . I ended up using 30 deg. total advance as the engine was still a long way from detonation and the A/F ratio was between 11.7 and 12.7 at higher revs . I have locked out the dizzy and have a full 30 deg. at idle . I also have a 20 deg. retard through the MSD box to make starting a little easier . The new 2'' exaught that I made seems to work good however it may now be a little small . I am using Sunoco Supreme Nos fuel and with an octane rating of 120 , it's good stuff . I also tried some VP c16 fuel and lost 10 rear wheel hp . To make more power I would have to increase the timing and take the chance of detonating . I unfortunatly didn't get the chance to run without the vacuum pump to see if it makes a difference but the engine has no oil leaks at all which really suprises me after the amount of work it has done already . I will post the results of racing soon , ROD.
More boost + More fuel = More power
1968 Beetle fastest run 8.96 sec @ 161 mph 4th Nov. 2001
2010 New Beetle 8.12 sec on 8th march 2014 http://www.rodpenroseracing.com.au
Hearing about all this VW drag racing make me want to build a rat drag car out of my 56 oval and get the Autocraft engine that I know of locally that can be had for reasonable money.....hmmm.....you're all a bad influence on me...
Hearing about all this VW drag racing make me want to build a rat drag car out of my 56 oval and get the Autocraft engine that I know of locally that can be had for reasonable money.....hmmm.....you're all a bad influence on me...
[ Edited on 17-5-2007 by reub-revhead ]
Reub, i've had you reported to the VW police!
NO YOU ARE NOT ALLOWED TO CHOP UP THE OVAL AND MAKE A RACE CAR OUT OF IT!!! 😀
Unfortunatley I went to start the car for a final tune at 6.00 pm on friday night and have broken the camshaft . I will not rebiuld it tonight so I will not be racing tomorrow . Sorry for the inconvienence I may have caused any person regarding racing . I will strip the engine tomorrow instead and find out what has gone wrong , ROD.
More boost + More fuel = More power
1968 Beetle fastest run 8.96 sec @ 161 mph 4th Nov. 2001
2010 New Beetle 8.12 sec on 8th march 2014 http://www.rodpenroseracing.com.au
Whilst on the dyno on Wed , I had a head stud nut fall off . I didn't think much of this as it was one of the extra 8mm studs and not the main studs . However , after so much running on the dyno the stud had vibrated out . or I should say in . Maybe because of the vacuum pump , and the stud has been forced between the crankshaft and camshaft therefore breaking the cam into 3 pieces . I am disapointed that I didn't make it to the compak attack but am relieved that it didn't happen at full power . At this stage I need another camshaft , lifters , 2 pushrods and a set of cam bearings . I will also get the crank and rods cracktested and inspect the rest of the engine before reassembly and hopefully back on the track in 3-4 weeks , ROD.
More boost + More fuel = More power
1968 Beetle fastest run 8.96 sec @ 161 mph 4th Nov. 2001
2010 New Beetle 8.12 sec on 8th march 2014 http://www.rodpenroseracing.com.au
OwenMM wrote:something to do with the fact the RPM is actually dyno speed, not engine rpm.
Ooh, that sounds like trouble.
I would have thought that the rollers would only be going 1/4 to 1/5 of the engine speed,
and then it would be a percentage, and not just an 'add-on'.
When I went to the dyno, it was quite crude also,
and the operator had to align the dyno scale
with the tacho in the car, and where the rev limiter cut in.
It is attention to details like this that give a lot of detailed info for future comparison on the dyno.
Afterall, HP is a calculation derived form the torque reading and RPM,
so if one is not accurate...you know what I mean.
Despite this I now enough to say that I think the rear wheel power IS correct,
and that engine IS a record setter.
Also,
And this is no personal criticism of Rodney at all because I have the greatest respect,
Because of the formula to work out HP from the torque reading,
HP and ft.lbs are always equal at 5252rpm.
This is not the case above, so I assume you would have to divide the torque figure by the gear ratio used and this would be more accurate.
The HP at the wheels uses the ROLLER RPM and the ROLLER TORQUE in this formula:
I believe it is a percentage, but 800rpm is just a convenient figure Jason gave to Rod to keep things simple. The dyno I used to use at work we would run it up to 100km/h on the dyno before a run and enter the rpm so it would display the readout in engine rpm, regardless of ratio used. Still not real accurate as your relying on reading the tacho visually off the car.
We did start the day with an rpm input on one of the leads, but had to take it off as the lead from the dyno was a bit short and as the car would ramp up the lead was pulling. Wasnt long enough for rear engine cars.
All of the new parts have arrived except for the camshaft which should be here tomorrow . I will rebuild the engine to the exact same spec's as before but with the addition of a new set of valve springs . The old springs were tested and only had 375 lb's of pressure @ .557'' lift , the new k 800 springs tested @ 467 lb's at full lift . I think that these are a little weak and the engine may have a little valve float causing a misfire at high rpm's . I will post some pic's and try to explain the best I can what I am doing during the rebuild . I have ordered 2 cams so I can build a spare engine in which I will inject lot of nitrous oxide into just to see what can be gained . I will be at WSID on June 23rd for a bracket meeting if all goes well , ROD,
More boost + More fuel = More power
1968 Beetle fastest run 8.96 sec @ 161 mph 4th Nov. 2001
2010 New Beetle 8.12 sec on 8th march 2014 http://www.rodpenroseracing.com.au
The engine is almost complete and I have entered to race at WSID on June 23 . I haven't had the time to post the pic's of the rebuild , however I have all pic's and will fill in the blanks over the next 2-3 weeks . All looks good at this stage for next weekend and am hoping for no more mishaps , I will keep you posted , ROD.
More boost + More fuel = More power
1968 Beetle fastest run 8.96 sec @ 161 mph 4th Nov. 2001
2010 New Beetle 8.12 sec on 8th march 2014 http://www.rodpenroseracing.com.au
The engine is in , started and tuned . I have had a smooth run in period and have now replaced the valve springs and I'm ready for this weekend . I need to pick up some race fuel from Sydney sometime this week and am looking forward to driving again , ROD .
More boost + More fuel = More power
1968 Beetle fastest run 8.96 sec @ 161 mph 4th Nov. 2001
2010 New Beetle 8.12 sec on 8th march 2014 http://www.rodpenroseracing.com.au
